b) I haven't been on a plane before
c) My pen has disappeared!
d) Nicky and Jan moved away from this school
e) I've just seen a friend of yours
f) I haven't finished writing my letters yet.
g) Have you ever been to South Africa before?
h) I forgot my wallet in the car
i) We haven't spoken to your sister for a long time
j) Has Anna woken up yet?
